Laser light irradiation apparatus

ABSTRACT

A laser light irradiation apparatus used for medical treatment of living tissues. According to a preferred embodiment, the apparatus comprises a probe and a plural number of optical fibers. The optical fibers surround the axis of the probe. Laser light goes through each optical fiber and is applied to the probe. Then, the laser light is emitted from the probe to uniformly irradiate the tissues, and if desired, against the tissues over a broad area. Further, a guide wire and/or a lead wire for detecting a temperature can be placed so as to be coaxial with the probe. Therefore, a perforation of a normal part of the blood vessel can be prevented.

This application is a continuation of application Ser. No. 07/575,905filed Aug. 31, 1990 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a laser light irradiation apparatus, whichirradiates laser light to living tissues of an animal such as a humanbody for use an incision, vaporization of the living tissues or athermal therapy and in case of widening a narrow path of the livingtissues such as a stricture part caused by cholesterol formed in theblood vessel of the human body.

2. Prior Art

Medical treatments such as incisions of living tissues of animalorganisms by irradiation with laser light are now conspicuous due to theability of hemostasis.

It had been the conventional method that the laser light was irradiatedfrom the fore end of an optical fiber retained out of contact with theliving tissues. But this method causes severe damage to the fore endportion of the optical fiber. Therefore, a method using a contact probewhich has been utilized lately is as follows:

First, laser light is transmitted into an optical fiber, whose fore endportion locates adjacent to treated living tissues. Next, the laserlight fed out from the optical fiber is fed into an emitting probe,which may or may not contact the living tissues. Then, the laser lightis emitted from the surface of the probe to be irradiated against theliving tissues. In this case, the probe should be brought into contactwith the living tissues (hereafter "living tissue" is sometimesexpressed by "tissue" only).

The Applicant developed many kinds of contact probes which are utilizedfor various purposes.

On the other hand, Applicant proposed in Japanese Patent Application No.63-171688, (Laid-Open No. 2-34161) a laser light medical treatmentequipment for burning off a stricture part caused by cholesterol formedon the inner wall of a blood vessel.

Before this invention, that is Japanese Patent Application No.63-171688, for the treatment for the stricture part, a heat wire probewas inserted into the stricture part. Then, since the heat wire probewas heated as a whole, there was a risk that a normal blood vessel otherthan the stricture part was damaged. Therefore, in order to prevent thenormal blood vessel from being damaged, the laser light medicaltreatment equipment of this invention was proposed. According to thisequipment, while a laser light emitting probe is progressed through theblood vessel to locate before the stricture part formed in the bloodvessel, the laser light is emitted so as to be irradiated against onlythe stricture part, which is beyond the probe.

Further, lately, a localized thermal therapy is drawing specialattention as a carcinostatic therapy. According to this method, cancertissues are destroyed by keeping the cancer tissues at a temperature ofabout 42°-44° C. for 10-25 minutes by laser light irradiation. Theeffectiveness of this method has been reported by the inventors in thebulletin of Japan Society of Laser Medicine, vol. 6, No. 3 (January1986), pp. 71-76 & 347-350.

On the other hand, considerable attention has been paid tolaser-chemical therapies including the method reported in 1987 byDougherty et al of the United States. According to this method, 48 hoursafter an intravenous injection of a hematoporphyrin derivative (HpD),weak laser-light such as argon laser or argon pigment laser isirradiated against a target area of the treatment. Whereupon oxygen ofthe primary term which has a strong carcinostatic action is produced byHpD. Since then, there have been published various reports in thisregard, including the one in the bulletin of Japan Society of LaserMedicine, vol. 6, No. 3 (January 1986), pp 113-116. In this connection,it has also been known in the art to use "pheophobide a" as aphoto-reactant. Further, recently, YAG laser has been put into use as alaser-light source.

In the above mentioned medical treatment, it is important that the laserlight is irradiated uniformly for the cancer tissues and, in case of thethermal therapy, it is particularly important that the cancer tissuesare heated uniformly.

Further, for heating the tissues uniformly, the Applicant disclosed inJapanese Patent Application Laid-Open No. 63-216579, that an apparatushas plural number of laser light emitters and an equipment for adjustingthe power level of the laser light impinging into the emitters.

If laser light is irradiated against the tissues from an optical fiberdirectly or through the intermediary of a contact probe, the power levelof the laser light irradiated against the tissues is the largest at acenter position of an irradiated area on the surface of the tissues. Thecenter position is contacted by the center of the optical fiber or thatof the contact probe, then, the power level is lowered as a position onthe surface of the tissues parts away from the above mentioned centerposition.

For example, as shown in FIG. 8, when the laser light is irradiatedagainst the tissues M with a contact probe P, in the temperaturedistribution of this figure, there is a peak at its center position andin the both sides in relation to this peak, the level is loweredgradually away from this peak. If the power level of the laser light israised, the size of this temperature distribution is also enlarged to bea substantial similar figure. However, the power level of the laserlight is increased to an excess level, the tissues corresponding to thepeak of the temperature distribution are damaged seriously. Accordingly,it is impossible to enlarge an irradiation area by only adjusting of thepower level of the laser light.

Therefore, it is difficult to irradiate the laser light uniformly, andparticularly more difficult to irradiate the laser light uniformlyagainst the tissues having broad area. Accordingly, within the limit ofthe predetermined power level of the laser light, laser lightirradiation against each small part of the tissues should be repeatedmany times in order to carry out the irradiation against all of thetreated tissues over a broad area. As a result, a medical operationcannot be carried out quickly.

Under these circumstances, as described before, the Applicant proposedin Japanese Patent Application Laid-Open No. 63-216579 that the pluralnumber of probes as the laser light emitters are provided and the laserlight is irradiated from each probe simultaneously.

Although the laser light can be irradiated against the tissues having abroad area to some degree by provision of the plural number of laserlight emitting probes, the necessity of a number of probes causes thefollowing problem.

For forming the uniform temperature distribution on the irradiatedtissues, the probes should be located at precise positions respectivelyso as to be contacted with the tissues uniformly. Therefore, the medicaloperation cannot be carried out quickly due to difficulties in preciselylocating the probes. On the other hand, since each optical fiber shouldcorrespond to each probe, the size of the apparatus is large.Accordingly, this apparatus cannot be used for a medical treatment in anarrow path in the tissues such as a catheter in a blood vessel.

On the other hand, in case of a treatment for a so-called angio-plasty,which means burning off the stricture part formed on the inner surfaceof the blood vessel to widen the inside of the blood vessel, asdescribed before, the Applicant proposed the laser light irradiationprobe. In this case, the probe can be used instead of the conventionalheat wire probe and is inserted into the blood vessel along the flexibleguide wire, which was inserted into the blood vessel previously.Further, in an embodiment of this proposal, in order to prevent theguide wire from being damaged by the laser light irradiation, the guidewire is placed so as to be deflected from the axis of the probe.

However, as shown in FIG. 13, deflection of the guide wire in relationto the axis of the probe causes the following problem. When a probe P isprogressed in the blood vessel until the probe P reaches at a bendingpart, due to the deflection of the guide wire, the probe P should beforced further in the blood vessel against the original bending part.Therefore, the bending manner at this original bending part of the bloodvessel is set to be changed to another bending manner. In this case,when the laser light is irradiated against the stricture part m, thereis the risk of breaking of the wall of the normal part of the bloodvessel BV other than the stricture part m or so-called perforationthere.

The energy districution of the laser light irradiation from the probeand the above mentioned temperature distribution shown in FIG. 8 have acommon characterization. That is to say, there is a peak at its centerposition and at both sides in relation to this peak, the power level oflaser light irradiation is lowered. Therefore, while the center of thestricture part m is completely burnt off, the inner wall of thestricture part m, which is away from the center, often still remains notburnt off. Accordingly, the power level of the laser light should beraised in order to burn off the whole stricture part completely.However, if a normal part of the inner wall of the blood vessel facesthe center of the emitting face of the probe due to the bending of theblood vessel, there is a risk that the normal part of the vessel may beburned during treatment.

SUMMARY OF THE INVENTION

It is therefore a main object of the present invention to provide asmall-sized laser light irradiation apparatus, by which laser light canbe irradiated against living tissues uniformly, if desired, against theliving tissues having a broad area, and in which a guide wire and a leadwire detecting a temperature are provided so as to be coaxial with apenetrating member for preventing the perforation at the normal part ofa narrow path having bending parts.

In order to solve the above mentioned problems, a laser lightirradiation apparatus of the present invention comprises a laser lighttransmissive emitting member and a plural number of laser lighttransmitting members. The transmitting members are provided so as tosurround the axis of the emitting member. Then, laser light goes througheach transmitting member so as to be fed into the emitting member andits fore end portion is buried in the transmissive material of theemitting member or adjacent to the impinging face of the emittingmember.

According to the present invention, the plural number of laser lighttransmitting members, usually optical fibers, are placed to surround theaxis of the laser light emitting member (this member hereinaftersometimes will be expressed by a probe). Therefore, for example, asshown in FIG. 6, in each power level of laser light irradiation from theemitting face of the probe, there is a peak at each axis of each opticalfiber. That is to say, as shown in FIG. 7, a whole power leveldistribution, which is produced by combining each power leveldistribution, shows a uniform and broad power level distribution.

For the angio-plasty in the conventional art, only the stricture in thecenter part of a blood vessel was mainly burnt off. However, by thepresent invention, the laser light is emitted also from thecircumferential part of the fore end face of the probe. Therefore, thematerial of the stricture along the inner wall of the blood vessel aswell as the center part thereof can be burnt off effectively. Due tothis complete burning, laser light emission with the high power level isnot required. Further, even if the blood vessel is bent, thereby, thenormal part of the inner wall of the blood vessel facing the centerposition of the emitting face of the probe, since the power level of thelaser light irradiation is not so high, there is not fear of perforationat the normal part of the blood vessel.

In thermal therapy, since the tissues having a broad area are heateduniformly, this therapy can be performed quickly and there is no riskthat the tissues at a center part of the irradiated area are seriouslydamaged seriously.

Further, while plural number of pairs of optical fibers and probes wereprovided in the conventional apparatus, in the apparatus of the presentinvention, a plural number of optical fibers correspond to one probe.Accordingly, although this apparatus also has a plural number of opticalfibers, the size of this apparatus is smaller than the conventionalapparatus. Therefore, the apparatus can be inserted into a narrow pathof organisms.

On the other hand, by forming a through-hole along the axis of theprobe, the laser light is not emitted from a center part of the fore endface of the probe. Accordingly, from the view of the whole power leveldistribution of the laser light irradiation, the laser light is emittedmore uniformly. Further, the guide wire can be inserted through thethrough-hole; thus, the guide wire can be provided at the center of theprobe. Therefore, when the probe is inserted along the guide wire, theprobe can be always set to locate at the center of the blood vessel asshown in FIG. 1. Therefore, the blood vessel is not forced to be bent,thereby, the perforation, which might be caused due to the bending ofthe blood vessel by the laser light irradiation against the normal partof the blood vessel, does not occur.

With this apparatus, the thermal therapy can be also performedefficiently. That is to say, the lead wire detecting the temperaturesuch as a thermocouple can be inserted through the through-hole so thatthe tip end of the lead wire can be pushed into the center of the targetarea to detect the temperature there for the efficient thermal therapy.However, in the prior art, since the thermocouple was provided so as topass around and attach along the side of a probe, the thermocouple wasset to be inserted into a position deflected from the center of theirradiated target area. Comparing the prior art, in the presentinvention, as described above, the thermal therapy can be performedunder the precise temperature control due to the suitable location ofthe lead wire.

Particularly, in the case of thermal therapy, high power level of thelaser light is not required. Therefore, the material of the probe is notrequired to have a high heat resistance.

Almost all of the probes, which had been invented by applicant, arefabricated from a ceramic material such as sapphire and the like. Inorder to scatter the laser light with the conventional probes, only twomethods, in which the surface of each probe was roughened or a laserlight scattering surface layer was provided on the surface of eachprobe, can be found.

Since the probe fabricated from the ceramic material is excellent inheat resistance, the probe can be used effectively when heat resistanceis required. However, when the tissues are heated in the above mentionedthermal therapy and the like, the high power level of the laser light isnot required, that is to say, the probe can be worked sufficiently withthe low power level of the laser light.

As the result of research by Applicant, a synthetic resin material isfound to be used for the probe in the present invention. Then, byfabricating the synthetic resin material containing laser lightscattering particles to be a predetermined shape, the laser light fedinto the probe is scattered with the scattering particles in the probe.Therefore, the laser light is emitted in various directions from thesurface of the probe. This produces a large area of laser lightirradiation. Further, since the probe is fabricated from the syntheticresin material, the probe has also an advantage that it can be formed tobe many types of suitable shapes according to its usage.

Then, the probe can be formed from the synthetic resin material so thatthe lead wire detecting the temperature such as the lead wire having thethermocouple at its tip end can be inserted through the probe. In thiscase, the temperature is required to be detected at a position whichexists inside of the tissues and which is adjacent to the fore end ofthe probe being brought into contact with the surface of the tissues.Then, according to the present invention, detecting the temperature canbe carried out precisely due to the suitable location of the lead wire.However, in the prior art, the temperature at the above mentionedprecise position cannot be detected for the following reasons:

In the prior art, it has been known that the lead wire is providedseparately with the probe. Therefore, the thermocouple attached to thetip end of the lead wire is set to be pushed into the tissues at theside part of the probe. That is to say, the thermocouple cannot be setin the above mentioned precise position in the tissues due to theunsuitable location of the lead wire. Accordingly, it is impossible todetect the temperature precisely. Alternatively, it has been known thatthe lead wire is passed around the side surface of the probe and the tipend of the lead wire is attached to the tip end of the probe. By thismethod, the temperature at a point on the surface of the tissuesadjacent to the external surface of the fore end portion of thecontacted probe can be detected. However, the detected temperature isthat of the surface of the tissues or is not that of the inside of thetissues. As a result, by these conventional methods, it is impossible todetect the temperature at the precise position. Thus, the temperaturecontrol for heating the tissues can not be performed surely.

In the present invention, since the probe is fabricated from thesynthetic resin material, the through-hole can be formed along the axisof the probe and the lead wire can be inserted through the probe to fixthe wire integrally to the probe by molding. Then, the lead wire isprojected from the external surface of the fore end portion of theprobe. Accordingly, when the probe is brought into contact with thesurface of the tissues, the projecting portion of the lead wire can bepushed into the tissues together with the fore end portion of the probe.Therefore, the temperature at the precise position, which is adjacent tothe external surface of the fore end portion of the probe and whichexists inside of the tissues, can be detected. As a result, thisapparatus is excellent in temperature control for heating the tissues.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein preferred embodiments of the present invention areclearly shown.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of an important part of anirradiation apparatus in a first embodiment related to the presentinvention;

FIG. 2 is a sectional view taken on line II--II of FIG. 1;

FIG. 3 is a longitudinal sectional view of an important part of anirradiation apparatus, which is modified from the first embodiment;

FIG. 4 is an illustration showing an operation of an irradiationapparatus being inserted into a blood vessel;

FIG. 5 is a longitudinal sectional view of an important part of anirradiation apparatus carrying out a local thermal therapy for cancertissues;

FIG. 6 is a schematic illustration for a temperature distribution withthe apparatus of FIG. 5;

FIG. 7 is a plan view of the temperature distribution of FIG. 6;

FIG. 8 is a temperature distribution with a conventional apparatus;

FIG. 9 is a longitudinal sectional view of an irradiation apparatus inanother embodiment;

FIG. 10 is a sectional view taken on line X--X of FIG. 9;

FIG. 11 is a longitudinal sectional view of an important part of anirradiation apparatus in another embodiment;

FIG. 12 is a longitudinal sectional view showing an operation forforming an inserting guide prior to inserting of the apparatus of FIG.11 into living tissues;

FIG. 13 is a longitudinal sectional view showing an embodiment ofconventional plastic surgery for a blood vessel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, the present invention is described more particularly with severalkinds of embodiments.

FIGS. 1 and 2 show a first embodiment mainly for an angioplasty. A probe1 is fabricated from a synthetic resin material or ceramic and so on.The fore end face of the probe 1 is rounded off at its circumference inorder to decrease the friction caused by proceeding of the probe in ablood vessel at the inner wall of the vessel. A main tube 2 is providedso as to be coaxial with the probe 1 and is fabricated from a flexiblematerial such as the resin of tetrafluorethylene and the like. The probe1 and the main tube 2 are connected through the intermediary of a metalholder 3.

In the main tube 2, a plural number, four for example in FIG. 1, ofoptical fibers 4 are provided in parallel to each other and surroundingthe axis of the probe 1 and/or the axis of the main tube 2. Each opticalfiber 4 is connected to a laser light generator (not shown). Each tipportion of the optical fiber 1 is exposed to a core 4a. Each core 4a isadjacent to the back end face or the impinging face 1a of the probe 1.Each optical fiber 4 is inserted into the main tube 2 from an insertinghole 2a. Then, the fore end portion of the optical fiber 4 is supportedand surrounded by the holder 3. The base portion of the back sideportion of each optical fiber 4 in the main tube 2 is supported andsurrounded by a synthetic resin holder tube 5.

On the other hand, a through-hole 1A is formed to go through along theaxis of the probe 1 to communicate with the inner through-hole of theholder 3 and the holder tube 5. A conductive tube 6 is provided in themain tube 2 so as to be projected from the back end of the main tube 2.The tip end of the conductive tube 6 is inserted into the inner side ofthe holder tube 5. A guide wire 7 is inserted through the conductivetube 6, further through the inner side of the holder tube 5 and that ofthe holder 3 so as to be projected from the through-hole 1A of theprobe 1. The base side portion of the guide wire 7 is coated by asynthetic resin coating such as the resin of tetrafluorethylene. Thefore end portion of the guide wire 7 is tapered gently and is totallygold plated. The guide wire 7 has a spherical tip end. A lead wire 10detecting a temperature, which is used not for the angio-plasty but fora thermal therapy, is inserted through this apparatus.

This laser light irradiation apparatus is used as follows:

Before the apparatus is introduced into the human body, the guide wire 7is inserted through the apparatus. Next, the guide wire 7 is furtherinserted into the treated blood vessel BV so that the tip end of theguide wire 7 extends further than a stricture part m, which will beburnt off by laser light irradiation.

Then, the apparatus other than the guide wire 7 is inserted in the bloodvessel BV along the guide wire 7 so as to proceed until the externalsurface of the fore end portion of the probe 1 is adjacent to thestricture part m. Laser light is fed into each optical fiber 4 to beemitted from the core 4a of the optical fiber 4. The emitted laser lightreceiving into the impinging face of the probe 1, passes through thebody of the probe 1, and is emitted from the front surface of the foreend portion of the probe 1. Finally, the laser light is irradiatedagainst the stricture part m.

By the laser light irradiation, the stricture part m is burnt off towiden the inside of a blood vessel. If desired, as shown in FIG. 4,pressurized air or pressurized liquid is sent into a balloon 11connected between a probe 1 and a main tube 2, thus, the balloon 11 isexpanded and press the stricture part m. As a result, together with theabove mentioned burning off the inside of the blood vessel by the laserlight irradiation, the stricture part m can be broken mechanically.

As shown in FIG. 1, in the present invention, the laser light is emittedfrom the circumference of the fore end face of the probe 1. Therefore,the laser light is irradiated efficiently against the stricture part mformed on the inner wall of the blood vessel BV. Accordingly, thestricture part m can be burnt off sufficiently even if the power levelof the laser light is low.

When the laser light is irradiated against the stricture part m, thelaser light is irradiated against also the projecting part of the guidewire 7. Therefore, the surface of the fore end portion of the guide wire7 is coated by a gold plating layer 9 for preventing the surface frombeing damaged.

As shown in FIG. 3, if desired, a reflecting sleeve-like tube 12fabricated from a thin metal is provided on the inner side surface of athrough-hole 1A and a laser light reflecting layer such as a gold platedlayer is formed on the surface of the sleeve-like tube 12. Accordingly,laser light is reflected on the gold plated layer. Therefore, laserlight irradiation toward the axis of a probe 1 can be decreased.

The apparatus of the type described above is used for also the thermaltherapy efficiently. As shown in FIG. 5, a lead wire 10 detecting atemperature having a thermocouple 10a at its tip end is brought intocontact with the surface of cancer tissues M or is pushed into thecancer tissues M. Then, the probe 1 is brought into contact with thesurface of the cancer tissues M. As a result, the laser light having alow power level is irradiated against the tissues M from each opticalfiber 4 through the intermediary of the probe 1. In this case, the powerlevel of the irradiated laser light can be controlled so as to keep thetissues M at the temperature of about 42°-44° C.

As described above, the laser light is irradiated against the tissues Mfrom the fore end circumferential face of the probe 1, as shown in thetemperature distribution of FIGS. 6 and 7, comparing the temperaturedistribution of FIG. 8 with the conventional apparatus, the temperaturecan be controlled uniformly over a broad area.

Although the through-hole 1A is not always necessary, the through-hole1A is preferably provided in the apparatus to give the uniformtemperature distribution.

For example in FIG. 5, since the through-hole 1A is provided, the laserlight, which reaches at the inner side surface of the through-hole 1A,is partly refracted to penetrate through the through-hole 1A and partlyreflected to go toward the tip end of the apparatus. Comparing anapparatus having no through-hole, in case of the apparatus having thethrough-hole, the rate of the emitted laser light from the fore endcircumferential face of the probe 1 is more increased, thereby, moreuniform temperature distribution is obtained.

Further, although the number of the provided thermocouple 10a is one inthe apparatus of FIG. 5, a plural number of thermocouples are preferablyprovided which can contact several positions of the tissues M.Consequently, the temperature can be controlled more precisely.

According to the present invention, the probes having many kinds ofshapes can be used in many kinds of manners.

For example, as shown in FIGS. 9 and 10, a probe 20 fabricated from asynthetic resin material can be used. This probe 20 is connected to aflexible protection tube 22 fabricated from the resin oftetrafluorethylene and the like through the intermediary of a metalholder 21 having a sleeve-like connector 21A.

A supporting tube 23 fabricated from a synthetic resin material isprovided to be connected to the holder 21 on the inner side surface ofthe protection tube 22. In the supporting tube 23, six optical fibers 4are supported so as to surround the axis of the tube 23. Each opticalfiber 4 is optically connected to a laser light generator (not shown). Alead wire 10 detecting a temperature having a thermocouple 10a at itstip end is inserted through the holder 21 and the probe 20 so as toproject from the fore end portion of the probe 20. Then, the lead wire10 is connected to a temperature measuring unit (not shown). Then,according to the result of detecting the temperature, the power level ofthe laser light, which is fed into the optical fiber 4 from the laserlight generator, should be controlled. This controlling is carried outby, for example, adjusting a timer switch, which is provided between thelaser light generator and the back end of the optical fiber 4. The probe20 composes a substantially cylindrical part having a fore end facebeing rounded off at its circumference and another cylindrical part atthe back side of the probe 20 having a smaller radius than that of thesubstantial cylindrical part by the thickness of the holder 21. Thesetwo cylindrical parts are fixed integrally. The smaller cylindrical partof the probe 20 is fitted in the sleeve-like connector 21A. Adding tothis fitting, if desired, by using an adhesive between the matingsurfaces; a back end circumferential face of the larger cylindrical partof the probe 20 and the fore end circumferential face of the sleeve-likeconnector 21A for high strength in fixing.

A laser light reflective layer 24 is formed on the mating surfaces ofthe probe 20 and the holder 21, in this embodiment the circle fore endface of the holder 21 and the inner side face of the sleeve-likeconnector 21A. Although the reflective layer 24 is preferably goldplated to give a high heat resistance, it might be aluminum plated andthe like in view of the material of the layer. For forming the layer,vapor-deposit as well as plating can be used.

Further, the fore end portion of the optical fiber 4 is inserted to beburied in the material of the probe 20 and the fore end face of the core4a of each optical fiber 4 is contacted with the material of the probe20 directly without any gap.

The probe 20 of this embodiment contains laser light scatteringparticles and is fabricated from the laser light transmissive resinmaterial. The material is synthetic resin such as silicone resin,acrylic resin (more preferably, methyl methacrylate resin), carbonateresin, polyamide resin, polyethylene resin, urethane resin, polyesterresin and the like, more preferably, thermoplastic synthetic resin. Forthe laser light scattering particles, the material, which has a largerrefractive index for the laser light than that of the above mentionedsynthetic resin material of the probe, is used, for example, a naturalor an artificial material such as diamond, sapphire, quartz material,single crystal zirconium oxide, laser light penetrating synthetic resinhaving heat resistance (it is needless to say that it is different fromthe above mentioned synthetic resin material of the probe), laser lightreflective metal (such as gold, aluminum and the like), and theparticles on whose surface the above mentioned laser light reflectivemetal are coated to be a compound material.

On the other hand, if desired, the probe contains laser light absorbingparticles such as carbon, graphite, iron oxide, manganese dioxide andthe like together with the scattering particles. A portion of laserlight is scattered in the probe and emitted from the probe, but some ofthe laser light impinges on the absorbing particles to generate heatenergy to give a large effect of heating.

The above mentioned probe 20 of this embodiment is fabricated by moldingto a desired shape from the synthetic resin material, which is in amelted state and into which the scattering particles are dispersed. As aresult, the fore end portion of the optical fiber 4 is buried in thematerial of the probe 20 as shown in FIG. 9 and the middle part of thelead wire 10 detecting the temperature is buried in the material of theprobe 20 so as to be fixed integrally to the probe 20. Accordingly, forfabricating this apparatus, for example, the holder 21 is made easily bymoulding from one mould to which the material is poured, while theoptical fiber 4 and the lead wire 10 project from the circular fore endface of the holder 21.

The laser light irradiation apparatus of the type described above in thepresent invention is used, for example, in a following manner. The laserlight is generated from the laser light generator, while the apparatusconnected to an endoscope is surgically or physically inserted to atreated target area in a human body. The laser light from the laserlight generator is fed into the back end of each optical fiber 4 and istransmitted therein to be emitted from the fore end face of the core 4a.Then, the emitted laser light is fed into the probe 20 directly and ispenetrated therein to be emitted from its external surface, while thelaser light is repeatedly refracted on the scattering particles in theprobe 20. Therefore, as shown in FIG. 9, the laser light, after repeatedrefraction, is emitted from the external surface of the probe 20uniformly for irradiating the tissues. As a result, as shown in FIG. 9,the laser light reaching the internal surface of the sleeve-likeconnector 21A is reflected on the reflection layer 24. Therefore, thesleeve-like connector 21A and the metal holder 21 are prevented frombeing heated and from being damaged, further, the reflected laser lightis brought forward.

Laser light irradiation of this embodiment is carried out in the samemanner as that of the embodiment shown in FIG. 5. That is to say, whilethe external surface of the fore end portion of the probe 20 is broughtinto contact with cancer tissues M, the projecting portion of the leadwire 10 from the external surface of the fore end portion of the probe20, is pushed into the tissues M. Then, the temperature of the tissues Mis detected with the thermocouple 10a for controlling the power level ofthe laser light fed into the optical fiber 4, in other words, the powerlevel of the laser light emitted from the external surface of the probe20, as described before. Then, the cancer tissues M are destroyed bykeeping the tissues M at the temperature of about 42°-44° C.

On the other hand, the laser light also irradiates the lead wire 10detecting the temperature in the probe 10. Therefore, in order toprevent the lead wire 10 from being heated and from being damaged, thewire 10 is preferably coated with a laser light reflecting layer such asa gold plated layer and a titanium coating layer like the laser lightreflecting layer for the above mentioned guide wire 7 of FIG. 1.

FIG. 11 shows another embodiment. The apparatus of this embodiment isused effectively in a treatment not for the surface of tissues but forinside of the tissues.

A probe 31 and plural number of optical fibers 30 are provided in thisapparatus. At the fore end portion of each optical fiber 30, a clad 30Bis removed so that a core 30A is exposed. The tip end of the core 30A istapered. A laser light scattering layer is formed on almost all of theexternal surface of the core 30A. In this figure, this laser lightscattering layer is illustrated by marking dots. For forming thisscattering layer, first, ceramic powders such as silicon dioxide and thelike are sprayed and heated to a temperature which is slightly lowerthan its melting point. Therefore, the original sprayed powders do notbecome homogeneous due to incomplete heating. Then, these incompletelyheated ceramic powders are cooled. Accordingly, the laser lightscattering layer can be formed on the core 30A, where the powders partlymelt and partly remain. Due to this scattering layer, when the laserlight is emitted from the external surface of the core 30A, the laserlight impinges on each resulting ceramic powder with refraction to bescattered.

On the other hand, the probe 31 is provided so that the cores 30A, eachof which is covered with this scattering layer, are buried in thematerial of the probe 31. The material of the probe 31 is fabricatedfrom synthetic resin containing scattering particles in the same manneras the embodiment of FIG. 9.

Lead wires 32 detecting temperatures are provided to be connected to thecores 30B respectively. The external surface of each lead wire 32 isgold plated. Then, the tip end of each lead wire 32 locates adjacent tothe back end face of the probe 31. The lead wires 32 together with theoptical fibers 30 are surrounded by a flexible sheath 33, which isfabricated from synthetic resin such as polyethylene, urethane and thelike, silicone rubber and so on. By moulding, the sheath 33 is fixedintegrally to the lead wires 32, the optical fibers 30 and the probe 31.

In case of applying this apparatus of this embodiment, as shown in FIG.12, first, a so-called puncture needle 35 together with a guide tube 34is inserted into the tissues M such as lever tissues. Next, only thepuncture needle 35 is removed. Then, instead of the needle 35, the foreend portion of this laser light irradiation apparatus is inserted intothe tissues M so as to go through the guide tube 34. Then, the laserlight is fed into each optical fiber 30 to be emitted from each core 30Aprovided at the fore end portion of the optical fiber 30. As so doing,the laser light is scattered in the scattering layer covering each core30A. Then, the scattered and emitted laser light is fed into the probe31 and goes through it, while the laser light repeats to be scatteredwith the scattering particles in the probe 31. At last, the laser lightis emitted from the external surface of the probe 31 uniformly. Thisapparatus is applied for a local thermal therapy for cancer tissues in aliver encephalic malignant tumors and cancer tissues in a breast.

The scattering particles contained in the scattering layer are basicallythe same as the above mentioned scattering particles in the probe.However, the particles, which cannot make a film when they melt, are notsuitable, thus, ceramic particles are generally used for the scatteringparticles.

Further, if desired, surface layers might be formed on the surfaces ofthe above mentioned several kinds of probes or the surfaces of the abovementioned scattering surface layers covered on the cores 30A of FIG. 11respectively to give a large scattering effect. This surface layercontains light scattering particles, which have a larger refractiveindex than that of the material of the probe or that of the abovementioned synthetic resin material. For example, sapphire, silicondioxide, aluminum oxide and the like are used as the scatteringparticles. Then, the surface layer also contains laser light absorbingparticles, which can be included in the probe as described before, suchas carbon and the like. Finally, the surface layer contains a binder,which adheres the particles to each surface and forms a film on thesurface as described hereinafter.

Due to the surface layer, the laser light is scattered by the lightscattering particles, further, when the laser light impinges on thelaser light absorbing particles, the greater part of the energy of thelaser light is converted to heat energy.

As the vaporization of the tissues is accelerated, the tissues can beincised with the laser light having the low power level of energypenetrated into the probe. Therefore, when the tissues are incised, theprobe can be moved rapidly. Further, since the required energy of thelaser light penetrating into the probe is low, the medical operation canbe carried out in short time with an inexpensive and small scaled laserlight generator.

On the other hand, referring to the surface layer, if a dispersioncontaining the laser light absorbing particles and the light scatteringparticles was coated on the surface of the probe, after a vaporizationof a dispersion medium, the contact of this probe with the tissues orother substances would cause a damage to the surface layer, because bothkinds of particles are attached to the surface of the probe only byphysical adsorptive power.

Therefore, by the binder which sticks the laser light absorbingparticles and the light scattering particles to the surface of theprobe, an adhesion of the surface layer to the probe is enhanced. Inthis case, the binder is preferably made of light penetrating particlessuch as synthetic resin particles or ceramic particles such as quartzparticles and the like. For forming the film, when the synthetic resinparticles are used as the material of the binder, the particles shouldbe melted, or when the ceramic particles having a higher melting pointthan that of the probe are used, the surface of the probe should bemelted.

Further, by forming a rough surface on the surface of the probe or byforming the above mentioned surface layer on the rough surface, thelaser light can be irradiated more effectively, because the laser lightis scattered on the rough surface when the laser light is emitted. Ifdesired, the rough surface is formed on the above mentioned core 30A;further, the above mentioned scattering layer might be formed on thisrough surface.

Although in the above mentioned embodiments shown in FIGS. 9 and 11,each core 4a or 30A of each optical fiber 4 or 30 is buried in thematerial of the probe 20 or 31, in other embodiments of the presentinvention, the fore end face of each optical fiber is located so as tobe apart from the back end (impinging) face of each probe. In this case,impurities such as dusts and the like are produced in the gap; further,impurities are attached to the back end face of each probe and the foreend face of each optical fiber. Accordingly, since the laser light isimpinged on the impurities, the back end face of the probe is heated.That is to say, the power level of the laser light fed into the probe islowered. Therefore, if the probe is fabricated from the synthetic resinmaterial thereby the optical fiber is molded to be fixed integrally tothe probe easily, the fore end portion of the optical fiber ispreferably embedded in the synthetic material of the probe.

While preferred embodiments have been described, it is apparent that thepresent invention is not limited to the specific embodiments thereof.

What is claimed is:
 1. A laser light irradiation apparatus comprising:alaser light emitting member; a plurality of laser light transmittingmembers, located around an axis of said emitting member, wherein a foreend portion of each of the transmitting members couples laser light tosaid emitting member; and a lead wire for detecting a temperature, whichextends through said light emitting member so as to project from a lightemitting surface of the light emitting member.
 2. An apparatus accordingto claim 1, wherein a through-hole is formed along the axis of saidemitting member.
 3. An apparatus according to claim 2, furthercomprising a flexible guide wire, for guiding said light emittingmember, wherein said flexible guide wire is inserted through saidthrough-hole.
 4. An apparatus according to claim 2, wherein said leadwire for detecting a temperature is inserted through said through-hole.5. An apparatus according to claim 3, further comprising at least oneadditional lead wire for detecting temperature wherein tip ends of saidlead wires can be brought into contact with corresponding positionsrespectively in tissues said laser light is irradiated against.
 6. Anapparatus according to claim 1, further comprising means for adjustingpower level of laser light transmitted through said laser lighttransmitting members in response to the detection of temperature viasaid lead wire.
 7. An apparatus according to claim 2, wherein areflecting layer is formed on an inner surface of said through-hole. 8.An apparatus according to claim 7, wherein said reflecting layer is agold plated layer.
 9. An apparatus according to claim 1, wherein saidlaser light transmitting members are optical fibers.
 10. An apparatusaccording to claim 1, wherein at least the portion of said lead wireextending through and projecting from the light emitting surface of saidlight emitting member are coated with a laser light reflecting material.11. An apparatus according to claim 1, further comprising a surfacelayer formed on the light emitting surface of said light emittingmember, wherein said surface layer contains laser light absorbingparticles, light scattering particles which have a larger refractiveindex than that of said light emitting member and a laser lighttransmissive material as a binder.
 12. A laser light irradiationapparatus comprising:a light emitting member; at least one transmittingmember, through which laser light is transmitted so as to be applied tothe light emitting member; and a lead wire for detecting a temperature,which extends through the light emitting member so as to project from alight emitting surface of the light emitting member.
 13. An apparatus asin claim 12, wherein a part of the lead wire which passes through thelight emitting member is embedded in the material of the light emittingmember.
 14. An apparatus as in claim 12, wherein the light emittingmember has a bore therethrough and said lead wire passes through thebore in the emitting member.
 15. An apparatus as in claim 14, furthercomprising a reflective coating located on the inner surface of the borethrough the light emitting member.
 16. An apparatus as in claim 12,wherein said at least one transmitting member, comprises at least oneoptical fiber, an end of said at least one optical fiber being exposedand held adjacent to a light receiving surface of the light emittingmember.
 17. An apparatus as in claim 12, further comprising a reflectivecoating on said lead wire.